1. Technical Field
The present disclosure relates to an optical touch screen device and a related hand-writing system.
2. Description of Related Art
A touch panel incorporated into a thin film transistor (TFT) liquid crystal display (LCD) has been proposed. A typical LCD includes a pair of glass plates which are separated by a layer of liquid crystal material. Commonly, the touch panel can be selected from a resistive touch panel and a capacitive touch panel.
In the above described LCD, the touch panel is usually attached to a display screen of the LCD. A number of resistors or capacitors are installed in the touch panel and are arranged in an array. When a stylus touches the touch panel, resistances/capacitances of some resistors/capacitors are changed. Thus, a position of the stylus on the written panel is sensed according to the change of the resistances/capacitances of the resistors/capacitors. However, the resistances/capacitances cause the touch panel to have a complex manufacture procedure. This increases cost and reduces production efficiency.
Therefore, an optical touch screen device and a hand-writing system which can overcome the above mentioned problems is desired.